METHOD FOR PRODUCING A WORKING AREA FOR A ROOT CANAL INSTRUMENT AND FOR PRODUCING A ROOT CANAL INSTRUMENT, AND ROOT CANAL INSTRUMENT

Abstract

A method of producing a working area for a root canal instrument includes the steps of providing a strand made of a nickel-titanium alloy, cutting the strand to a blank size of the working area, forming a tip in the working area, heat-treating the working area at a temperature of 400 to 430? C. for 25 to 40 minutes, quenching the heat-treated working area to room temperature, and producing the final geometry of the working area, wherein the nickel-titanium alloy contains exclusively nickel and titanium as metal components.

Claims

1. A method of manufacturing a working area for a root canal instrument comprising the steps: providing a strand made of a nickel-titanium alloy cutting the strand to a blank size of the working area forming a tip in the working area heat-treating the working area at a temperature of 400 to 430? C. for 25 to 40 minutes quenching of the heat-treated working area to room temperature; and producing a final geometry of the working area wherein the nickel-titanium alloy contains exclusively nickel and titanium as metal components.

2. The method according to claim 1, wherein the heat treatment is carried out by applying a resistive process.

3. The method according to claim 1, wherein the nickel-titanium alloy comprises carbon and/or oxygen as further components.

4. The method according to claim 1, wherein the nickel-titanium alloy consists of 54 to 57 mass % nickel, a maximum of 0.05 mass % carbon, a maximum of 0.05 mass % oxygen, and the balance titanium.

5. The method according to claim 1, further comprising a step of rounding the working area after forming the tip and before heat treatment.

6. The method according to claim 1, wherein the quenching is carried out in water.

7. The method according to claim 1, wherein producing the final geometry of the working area comprises grinding a toothing and/or a depth mark.

8. The method according to claim 7, wherein the depth mark is ground into an area discolored by the heat-treating and quenching.

9. The method of manufacturing a root canal instrument, comprising the steps: producing a working area for the root canal instrument according to the method of claim 1, and connecting the working area to a shaft.

10. The method according to claim 9, wherein the connection of the working area to the shaft is carried out by pressing, welding or molding.

11. The method according to claim 9, further comprising a step of color marking and/or a step of mounting a stopper.

12. A root canal instrument manufactured by a method according to claim 9.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In the following, the invention is described by means of an embodiment example in connection with the drawing. The FIGURES show in:

[0027] FIG. 1 a schematic side view of a root canal instrument according to one embodiment of the invention.

DETAILED DESCRIPTION

[0028] FIG. 1 shows in detail a root canal instrument 1 produced according to the method of producing a root canal instrument according to the invention, comprising a shaft 2 and a working area 4 connected to the shaft 2 by a connection area 3. A connection piece 5 is located at a distal end of the shaft 2. The connection piece 5 is used for connection to a drive or also a handpiece with which a dentist can operate the root canal instrument 1.

[0029] The working area 4 is to be regarded as a cutting area with which dead or bacterially infected pulp tissue of a root canal can be removed. The working area 4 comprises a first end 6 and a second end 7. The first end 6 is connected to the shaft 2 in the connection area 3, while the second end 7 is exposed and comprises a tip. Overall, the course of the working area 2 from the first end 6 to the second end 7 is more or less conical, wherein the working area 2 comprises a plurality of areas in the axial direction X-X that are provided with different twist angles, wherein the twist angles decrease from the first end 6 to the second end 7.

[0030] The working area 4 consists of a nickel-titanium alloy consisting in particular of 54 to 57 mass % nickel, a maximum of 0.05 mass % carbon, a maximum of 0.05 mass % oxygen, and the balance titanium. The working area 4 was obtained by cutting a strand of the nickel-titanium alloy to a blank size of the working area, forming a tip in the working area, heat treating the working area at a temperature of 400 to 430? C. for 25 to 40 minutes and in particular at 400? C. for 30 minutes, quenching the heat treated working area to room temperature and producing the final geometry of the working area. Here, the heat treatment, which was carried out in a furnace as an example, and the subsequent quenching, which was carried out using water kept at room temperature (20 to 25? C.), were essential for obtaining a highly flexible but mechanically stable working area, which was joined to the shaft 2 after the final geometry was produced.

[0031] As an alternative to heat treatment in a furnace, the required heat can also be applied via a resistive process. In this case, a voltage is applied to the component to be heated, with the current flow being regulated to approx. 5 A per component. The component can be contacted with the voltage source via a mechanical sliding contact or alternatively via a conductive electrolyte.

LIST OF REFERENCE CHARACTERS

[0032] 1 root canal instrument [0033] 2 shaft [0034] 3 connection area [0035] 4 working area [0036] 5 connection piece [0037] 6 first end [0038] 7 second end